Chatoyancy: Yes, It Really is a Word

Chatoyant derives from the French verb chatoyer that literally means "to shine like a cat's eyes.  In wood, the word chatoyant is used to describe the way light refracts on abrupt changes in grain direction.  This phenomena occurs in burls and crotches.  When you move the wood in the light it seems to give off iridescence from within.  It almost looks three dimensional.

Below are several examples of wood with figure that has chatoyancy.